In the past, an inspection system for detecting the roughness of the surface of an object being inspected has been proposed (for example, see Patent Document 1). In this type of inspection system, a laser beam is fired at the surface of an object being inspected and the amount of laser beam scattered and reflected at that object surface is measured. Furthermore, information showing the surface roughness of the object surface is generated based on the measured amount. According to this inspection system, it becomes possible to objectively inspect the surface roughness of a semiconductor wafer etc.    Patent Document 1: Japanese Patent Publication (A) No. 6-244261